Method of electroplating



Nov. 6 i923. 11,473,096@

E. N. TAYLOR METHOD OF' ELECTROPLATING Filed Dec. 17. 19.21

Patented Nov. 6, i923.

Uhllflll@ STATES l anatre@ serena onirica EDWARD N. TAYLOR, F ST. LOUIS, MISSOURL ASSIGNOR T0 WALTER A. ZELNICKER,

OF ST. LOUIS, MISSOURI.

METHOD '0F ELECTROPLATNG.

Application led December 17, 1921. Serial No. 523,174.

To all whom t may concern.'

Be it known that I, EDWARD N. TAYLOR, a citizen of the United States of America, and a resident of the city of St. Louis and State of Missouri, have invented certain new and useful Improvements in Methods of Electroi plating, of which the following is a full,

clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to improvements in methods of electro-plating, the main object being to provide a method or process^of this kind whereby a. smooth, uniform coating of metal is deposited on the surface of the object undergoing the plating operation.

Prior to this invention, tiny gas bubbles and solid impurities have collected on surfaces being plated in an electro-plating solution, and' as a consequence numerous small pits have been found in the plated surface. This is especially true of articles plated with zinc in the usual manner, it being customary to avoid any forcible disturbance of the solution at the surface on which the metal is deposited, and foreign matter such as solid impurities and minute gas bubbles is permitted to cling to this surface, with the result of very materially impairing the appearance and durability of the. plating.

l am aware that gas bubbles and the like can be removed by imparting a constant rapid motion to the article in the electroplating solution, but a continuous motion of this kind results in an undesirable coarse, crystalline deposit.

lt will now be understood that in one of the old methods there is no forcible disturbance of the solution at the surface to be plated', and this method produces a plated surface having numerous small pits, and on the other hand, if either the` article or the solution is constantly in motion or con-l stantly displaced, a coarse, crystalline deposit will be formed on the surface. of the article.

My object is to obtain a smooth, uniform, tenacious and durable coating firmly adhering to the surface of the work. and this is accomplished by a new method in which gas bubbles. and the like, are intermittently removed' from the deposit on the article in the electro-plating solution. stated, the solution and the article are permitted to remain quiescent for relatively More specically ving the article being plated, or byotherwise acting. upon the solution to wash away the impurities on the deposit. Actual experence has shown that very satisfactory results can be obtained by rapidly moving the article for a period of three seconds during each minute, and permitting the article and solution to remain quiet, or nearly so, during the other tifty-seven seconds. lt is to be understood, however, that the invention is not limited to the preferred form of the invention as herein set forth.

Fig. ll is a diagrammatical View of an apparatus adapted for use in carrying out the new method.

Fig. H is a View similar to Fig. l, showing another apparatus.

Fig. Hl is a diagrammati-cal view of another apparatus adapt'ed for use in the new method'.

ln Fig. I, A designates a tank, or vat, containing an electro-platino solution in which an anode 1 and' a cathode 2 are submerged. The cathode may consists of a number of rings constituting the work, or object to be plated` said rings being,r secured to a vertical shaft 3 mounted in bearings 4 and 5 and providedl with a gear wheel 6 at its upper end. The wheel 6 is in mesh with a gear wheel 7 on a rotary shaft 8 provided with a pulley 9. An electric motor 10 is provided with a pulley 1l and a belt 12 whereby motion is transmitted to the pulley 9.

Through the medium of the mechanism just described. the cylindrical cathode 2 can he rotated' about its own axis. The means for energizing and controlling the motor l() comprises conductors 13 and 14 connected to the motor, the conductorlll being provided with a controlling switch 15 adapted to start and stop the motor.

The electro-plating apparatus shown by Fig. l may be considered as a zinc-plating apparatus involving the use of any suitable solution in the vat A. The electmc current may be transmitted through a positive wire 16 connected to the anode 1 and a negative wire 17 connected to a brush 18 engaging the rotary shaft 3 from which ythe cathode is suspended.

The motor 10 is operated at intervals to rotate the cathode 2 1n the solution, thereby violently agitating the solution around the cathode to forcibly wash away minute gas bubbles and other impurities that tend t0 accumulate on the deposit. In a zinc plating apparatus, I have found that highly satisfactory results can be obtained by driving the periphery of the cathode at the rate of 400 feet per minute for a period of three seconds during each minute, and permitting the cathode and solution to remain approximately still during the remaining fifty-seven seconds.

Fig. II shows an electro-plating apparatus wherein the cathode 2 is secured to a non-rotary rod 3 to which an electrical conductor 17 is connected. l is the anode suspended in the solution. A brush 20 is'pivoted to a crank arm 21 extending from a rotary sleeve 22 surrounding the rod 3 and mounted in a bearing 23. A gear wheel 6', fixed to sleeve 22, meshes With a gear Wheel 7 on a rotary shaft 8 provided with a pulley,

9. A motor 10 is provided with a pulley 11 and a belt 12 through which motion is transmitted to pulley 9. The motor is controlled by a switch 15.

The brush 20 is adapted to engage and revolve around the periphery of the cathode 2.l so as to remove bubbles and solid impurities from the deposit on the cathode. The motor 10 is operated intermittently to impart an intermittent rotary motion to the brush.

A latch member 25 is pivoted to the rotary sleeve 22 and provided with'a tooth adapted to engage a finger 26 extending from the handle of brush 20. Whenthe parts are positioned as shown in Fig. II, the latch member 25 cooperates with finger 26 to retain the brush in engagement with, or adjacent to, the cathode 2. During the intervals that the bruslris not in motion it is separated from the anode, and the tooth on latch member 25 will then cooperate with finger 26 to hold the brush away from the cathode.

In Fig. III the anode 18L and cathode 22l are suspended in the electro-plating Solution in a vat A. An Vair conducting pipe 27 is provided With a nozzle 2S arranged in the solution and located adjacent to the cathode 2a. Compressed air is transmitted through the pipe 27 and discharged. at the nozzle 28,

thereby agitating the solution and forcibly removing gas bubbles and solid impuritiesl from the deposit on the cathode 2. The ow of compressed air is controlled by a valve 29, andthis valve is intermittently opened and closed to agitate the solution for brief periods of time and to leave the solution in its normal quiescent state during longer intervening periods.

I claim:

1. The method of electro-plating which comprises plating the surface of an article in an electro-plating solution, permitting the solution to remain substantially quescent for relatively long periods of time, and forcibly removing foreign matter from said surface during shorter intervening periods.

2. The mehods of electro-plating which comprises plating the surface of an article in an electroplating solution, at the same time intermittently agitating the solution around said surface for brief periods of time to remove gas bubbles from the surface, and permitting the solution to remain quiescent for longer intervening periods.

3. The method of electro-plating which comprises plating the surface of an article in an electro-platingsolution, permitting the solution to remain substantially queiscent for relatively long periods of time, and violently agitating the solution around said surface during shorter inter-venin periods, so as to forcibly remove gas bub les from the deposit on said surface.

4:. The method of electro-plating which comprises plating the surface of an article in an electro-plating solution, and imparting an intermittent motion to the article.

5. The method of electro-plating which comprises plating the surface of an article in an electro-plating solution, and imparting a rapid intermittent motion to the article for brief periods of time, so as to-forci bly remove foreign matter from the deposit .on the surface of the article.

EDWARD N. TAYLOR. 

